As tickmeister pointed out, Oerter set Olympic records each time. Lewis did not (no one has bested Bob Beamon's 1968 Mexico City effort).
But were it not for Lewis, Oerter would have I think the record in track and field for consecutive Olympic golds.
no one has bested Bob Beamon’s 1968 Mexico City effort”
Actually, Mike Powell currently holds the world record. He broke it in the 1992 world championships in a showdown with Lewis.
But you are correct in that Beamon’s olympic record stands, absolutely.